I had exactly the same experience in building a glibc and gcc, and it was also on an old CentOS system on HPCs that are not updated and I do not have root privi

I had exactly the same experience in building a glibc and gcc, and it was also on an old CentOS system on HPCs that are not updated and I do not have root privilege to. I used linuxbrew to build glibc and gcc. In my case it was that VSCode remote delivers a node to remote machine that requires a new glibc, where the HPC does not have. I have to use patchelf to patch the node runtime in order for it to find the glibc libraries I built. I am so glad there finally more products that allows me to easily run newer software, and glad to see it is Arch Linux, which always have latest software and is my go to for dev machines.